Mix cream cheese, sour cream, lemon juice, slat, and pepper together in bowl until uniform, and then stir in shallot, capers, and chives or dill.

Spread 1 teaspoon cheese mixture evenly over each slice of salmon. Roll up salmon around cheese mixture. (at this point, salmon rolls can be covered tightly with palstic wrap and refrigerated for up to 4 hours).

Slice each salmon roll in half with sharp knife. Stand each roll on its cut end, garnish with arugula leaf, and serve.